1. Field of the Invention
The present invention relates to a wobble plate pump and motor assembly.
2. Background Information
U.S. Pat. No. 5,626,464 issued to Schoenmeyr et al. discloses a wobble plate pump that is produced by the assignee Aquatec Water Systems, Inc. The Aquatec pump has three pump pistons that move in a reciprocating manner within corresponding pump chambers. The reciprocating movement of the pistons pump fluid from an inlet port to an outlet port of the pump. The pistons are moved by a wobble plate that is rotated by an electric motor.
When a pump is initially activated there may be air in both the inlet and outlet lines. During start up the pump will undergo a priming phase wherein both fluid and air are pulled into the pump chambers. Because of gravity the fluid will tend to flow into and fill the lower pump chambers before filling the upper chamber(s). The filled lower pump chambers may create a back pressure in the outlet line that essentially traps air within the upper pump chamber(s). In a steady state operation the piston in the upper chamber merely compresses and expands the air and becomes inoperative. The loss of a chamber reduces the output of the pump. It would be desirable to provide a fluid pump that reduces the likelihood of air lock within the pump chambers.
The electronic motor that drives the wobble plate must be sealed by a diaphragm to prevent fluid from coming into contact with the motor windings and shorting the motor. The diaphragm may develop a crack that allows water to leak into the motor. The water may create an electrical short that damages the motor. It would be desirable to provide a leak detector that can detect leakage in the winding area. It would also be desirable provide a leak detector that is relatively inexpensive to incorporate into the motor assembly. Additionally, it would be desirable to provide a means to stop the pump upon detection of a leak to prevent damage to the motor.
Wobble plate water pumps typically contain a one-way outlet check valve that is integrated into the pump. The check valve may fail thereby rendering the pump inoperable. It would be desirable to provide a wobble plate pump that allows someone to replace the check valve.
The Aquatec pump has a plurality of inlet and outlet valves located within valve seats of the pumps. The valve seats are molded in a shape that is a segment of a sphere. It is difficult to mold a true spherical shape. Any non-conforming shape may create an improper seating of the valves. It would be desirable to provide valve seats that are easier to mold and still effective.